Unwanted noise and vibration limited the appeal of old diesel-powered vehicles. Jeep recognized that the engine was primarily responsible for unwanted buzzing and rattling, and therefore has added features to quiet the new mill. A noise-reducing engine cover, balancing shafts, an air induction resonator, and a torque converter turbine damper all contribute to quieter operation overall.

This new unit displaces 2.8-liters in an inline-4 configuration. Power is rated at 160 hp. at 3,800 rpm and 295 lb.-ft. of torque at 1,800 rpm. With a 20.5 gallon tank and fuel economy estimated in the mid 20s predictions are for 22 city/27 highway, which compares to the gasoline Liberty at 20/24) and a driving range of close to 500 miles. Notable is an impressive 5,000 lb. of towing capacity, a result of the torque. (This is 2 and ½ times the capacity of the 4-cylinder gasoline-engined Liberty and equal to the 6-cylinder version, which gets 17/22 fuel economy, by comparison.)

Fuel is delivered to the cylinders via direct injection at up to 24,000 psi. The injectors now burn fuel more efficiently, thereby reducing hydrocarbon emissions. Compared to diesels of the 1980s, this engine is approximately 60 percent cleaner.

Diesels have also been criticized for their sluggish performance. Subsequently, Jeep has attached a turbocharger to provide the needed boost. A moveable vane inside varies the impact of the turbo – during launches it acts like a “small” turbocharger and increases low-end torque, while at higher revs it works like a “large” turbo and provides top-end power. The new 2.8 is also quick to start, needing only two seconds to warm up the ceramic glow plugs.

We drove the new model on a somewhat rigorous “101 Off Road” course. Notable was its engine braking on steep hills and its overall handling, typical of other Libertys.

All diesel engines are backed by a 5-speed automatic transmission with overdrive. Other engine options include a 150-hp. 2.4-liter inline-4 and a 210-hp. 3.7-liter V6, both powered by gasoline.